Download the code from the repository. All the C++ dependencies required to build the code are included. It should work on Windows, macOS and Linux, and it should build out of the box with CMake:

mkdir build
cd build
cmake ..
make -j4

On Linux zenity is required for the file dialog window to work. On macOS and Windows the native windows are used directly.
The formula for higher order bases are computed at CMake time using an external python script. Consequently, PolyFEM requires a working installation of Python and some additional packages in order to build correctly: